This invention relates generally to solid propellant motors and more specifically to a system for measuring the response of solid propellants to externally imposed loads and environments.
Advancements in the field of solid propellant motors have included a multitude of various compositions designed to improve the efficiency and reliability as well as the storage and handling characteristics. The basic criteria for these alternative forms of solid propellant motors lies in the chemical makeup of the material rather than the physical properties expected. While the chemical aspects of composite propellants may be predicted with a reasonable degree of accuracy based on known data and experience, physical properties are more difficult to ascertain.
One of the principal drawbacks in accurately calculating the stresses, strains and deflections of solid propellant motor grains to externally imposed loads is the fact that the newness of composite propellants has not allowed the mechanical behavior of these grains to be fully understood. Hence, it is essential that these quantities be measured. Additional difficulties arise in the measurement of the quantities in that conventional transducers and the associated lead wires utilized to sense these mechanical states cause disturbances to the stress/strain field that is sought to be definined.
Therefore, a new and improved hydrostatic stress gage system has been invented which will overcome the disadvantages of the prior art devices and provide reliable, accurate means for measuring these parameters within a solid propellant motor